Casting machine



April 18, 1944. wEYHlNG 2,347,013

' CASTING MACHINE 7 Filed Aug. 2, 1940 v 2 Sheets-Sheet l INVENTOR. A MUST L. WEYH/w 1l BY ATM/i (IE Y- April 18, 1944. A. WEYHING CASTING MACHINE Filed Aug. 2, 1940 2 Sheets-Sheet 2 V IIIIIIII IIIIIIII IN VEN TOR.

Auausr L. WEYH/Nq ATTORNEY.

Patented Apr. 18, 1844 CASTING MACHINE August L. Wcyhing, Louisville, Ky., assignor to Edmund A. Steinbock, Louisville, Ky.

Application August 2, 1940, Serial No. 349,666

10 Claims.

This invention relates to improvements in a casting machine for casting metallic objects particularly such castings as are made for dental replacements.

It is one of the principal objects of this invention to provide a casting machine wherein the parts which support and cover the mold readily assume their proper alignment with respect to the mold prior to the application of pressure for forcing the molten metal into the mold and its crevices.

Another object of this invention is the provision, in a casting machine, of a mold support that has substantially universal movement for properly aligning the mold with the pressure plate of the casting machine to insure proper seal at the top of the mold by the pressure plate during the casting operation.

A further object of this invention is the provision in a casting machine accomplishing the foregoing object of means utilizing the movement of the mold support for opening the pressure control valve.

A still further object of this invention is the provision in a casting machine of a pressure plate mounted for substantially uiversal movement with respect to the mold for insuring proper seal by the pressure plate on the mold during the casting operation.

It is also an object of the invention to provide a casting machine which is relatively simple to operate, inexpensive to manufacture and-devoid of complicated parts and movements.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

Fig. 1 is a side elevationsl view of a casting machine embodying the improvements of this invention.

Fig; 2 is a view similar to Fig. 1 showing the parts in a position during which time a casting is being made.

Fig. 3 is a top plan view of the machine with the parts, substantially, in the position of Fig. 2. Fig. 4 is a vertical sectional view through the machine taken on line 4-4 on Fig. 1.

Fig. 5 is a fragmentary sectional view showing some of the parts in elevation and taken on line 5-5 on Fig. 1.

Fig. 6 is an enlarged fragmentary view of certain parts of Fig. 4 showing the construction of the pressure and sealing plates.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

As was noted above this invention pertains to a casting machine that is a machine in which air pressure is employed for forcing the molten metal into a mold. The machine will probably find its greatest uses in the dental field for making castings for replacement purposes in the mouth. The process of making replacement castings consists in making an impression of the part of the mouth to be replaced and then a wax pattern exact in all detail to the impression if the impression were not originally made in wax. This wax pattern or model is then suitably invested in an investment composition which constitutes the mold. The wax pattern or model is then dissipated by heat which results in a cavity having all of the detail of the wax pattern.

A finished mold is shown in broken lines in Fig. 4 and as there illustrated the reference numeral It) indicates the cavity from which extends a sprue hole H which terminates at its upper end in a concave depression l2 forming the crucible for the metal to be melted and forced into the cavity. These parts where formed by investing the wax patterns thereof in a cementitious mass I3 which was allowed to stand and harden to form the mold. The cementitious mass was poured into a metallic cylinder generally referred to as a sleeve M. It is this assembly that is placed on the casting machine to make the casting.

Referring now to the machine, it comprises a hollow casting [5 which constitutes the base for the machine and at the same time acts as an air pressure reservoir. Extending from the opposite sides of each end of the base If: are lugs H; which form the feet for the machine. Secured within the reservoir I5 is a pump cylinder 1! through which operates a pump piston it carried by the inner end of a piston rod [9. The piston rod 19 has secured to its outer end a knob 23 for actuating same and the rod is suitably packed as at 21 to prevent leakage. The other end of the base l5 has upstanding therefrom a hollow post 22 communicating with the reservoir in the base Secured to the upper end of the post 22 is an air gage 23 for indicating the pressure therein and in the reservoir.

The base-reservoir I illustrated in the drawings is substantially oval shaped in cross section, as illustrated in Fig. 4, and is therefore provided intermediate its ends with a flat portion 24 for the mold support. This mold supper, as seen in Fig. 4, comprises a disc 25 having an aperture 25 at its center the base of which is formed as a conical seat 27. Surrounding the bore 25 and depending from the disc 25 is a circular boss 28 received in one end of a coil.

spring 29. In alignment with the disc boss 28 is a boss 39 upstanding from the seat 2 5 disposed within the other end of the coil spring 25. Projecting through the aperture in the boss 28 of disc 25 is a bolt having its threaded end 3| screwed into a threaded socket in the boss 35 and with its head 32 in th disc aperture 25. The bolt between its head 32 and threaded portions 3| is provided with a'tapered shoulder which rests on the tapered bas 21 of the bore 25.

The bolt is sufficiently screwed into its socket to hold the disc 25 in position with the spring 29 under slight compression. As will be later pointed out, pressure on the disc 25 will permit it to deflect in the direction of said pressure and thereby permit the said disc 25 to tak a position other than parallel with the base and at an angle thereto. 1

Mounted on the disc 25 is a collar 34 which will vary in thickness depending upon the height of the ring M in order to bring the top of said rin to a normal height for contact by the sealing plate.

Below the disc 25 is located the arms 35 and 33 of the forked end 31 of a lever 38. The lever 38 i provided on its other end with a flat tail 3%. Intermediate its ends the lever 38 is pivoted at 30 between a pair of brackets M secured to the upper surface of the bas I5 behind its seat 2-4.

The fork lever 58 normally takes the position illustrated in Fig. 1 with the ends of the arms 35 and 35 contacting the undersurface of. the disc 25. The tall 38 of the lever is, at this time contacting the adjustable button 42' on valve stem 63 of air valve 4d. The stem 43 is spring biased to hold the button 42 and lever 38 in the position above described and clearly illustrated in Fig. 1. The valve 44 is threaded into the front face of the column and controls the flow of air therefrom and from the reservoir [5.

The upper end of the column 22 is narrowed in width as at 35 and received the arms 4-5 and 4'! of the "forked end 43 of operating lever 39. The column portion 45 and arms 46 and A? are respectively provided with an aperture in axial alignment with one another through which passes pivot bolt 58 whereby the lever 49 is operable toward and from the base l5. The operating lever 43 is provided intermediate its length with an enlarged boss-like portion 5i in which is mounted the meld pressure and seal plates.

Referring to Fig. 4 it will be noted that the boss 5! of the lever 48 is provided therethrough with. an aperture 52 the upper end of which is flared to provide a seat 53. The lower end of the aperture 52 communicates with a counterbore 54 let into the boss from the lower surface thereof and which counter-bore is provided. with a seat 55 at its base.

The aperture 52 of the boss 5! has extending therethrough a tube 58- which is provided at its, upper end with an enlarged collar-like portion 51. Connecting the collar 57 with the tube 55 is a conical portion 58 which rests on the lever boss seat 53. The lower end of the tube 56 is threaded to receive a lock nut 59 which lock nut also forms one abutment for a coil spring 55) which encircles the tube 55 and abuts on its other end with the counter-bore seat 55.

The tube 55, below the lock nut 59, has threaded thereon a disc Bl which may be referred to as a pressure plate. The pressure plate 61 is cup shape and has projecting centrally thereof below the tube 56 a boss 62 which may be termed a distributing head. This boss 62 is solid except for a series of extremely small air holes which eiiiect communication between the tube 55 and atmosphere below the plate 6|. In addition the boss or distributing head 62 has threaded centrally thereof a screw 64 which is employed by having its head more or less restrict the flow through the small bores 53 and thereby regulate the air flow through the distributing head. The boss or distributing head 62 is externally threaded to receive a second cup shaped disc 65 which may be termed the sealing plate. Pressed into the cup of the sealing plate 55 is a relatively soft material 66 preferably asbestos.

The upper end of the tube 56 is provided with a small hose coupling 61 to which is secured one end of a piece of hose 58' which in turn has its other end connected to a hose coupling 69 projecting from the rear side of air valve M Extending from the operating lever boss is a lug H! received between the arms H and 1?. of the fork end T3 of a latch M. The latch 14 terminates in a nose which has a plane face it which is vertically disposed when the latch is in its operative position as will later be made clear. The latch face 15 cooperates With an abutment screw or bolt Tl threaded into an extension it at the top of post or column 22.

The operation of the mechanism is as follows:

The mold is prepared in the ring- M as above described whereupon the ring is placed on the collar 34 on the disc 25. It is to be understood that at this time the operating handle 49 is elevated to its inoperative position which is almost vertical of the base l5. At this time the pressure and sealing plates andother parts associated therewith have the angular position with respect to the operating handle 49 as illustrated in Fig. 1. At this time also the work, that is, mold support and parts associated therewith are in the angular position with respect to the base l5 as illustrated in Fig. l. The pressure plate assembly and mold support assembly are respectively held in these normal positions by the springs 50 and 29.

Metal in nugget form is placed in the crucible l2 and heat applied to melt same whereupon the operating handle 19 is moved to the position shown in Fig. 1 with the sealing plate lining 66 in contact with the corner of the ring I4. The operating lever is immediately continued in its r movement downwardly toward the base l5 to the position illustrated in Fig. 2.

During the movement of the operating handle 49 from the position of Fig. 1 to that of Fig. 2 the springs 60- and 29 where compressed and the various assemblie rocked so that the upper surface of the ring l4 and under surface of the sealing material 66 werev disposed in the same plane and in sealing contact with one another. As the mold assembly was depressed the disc 25 through the forked end 31 oscillates the lever 38 and through the lever tail 39 depresses the valve plunger for opening same and thereby per mitting an air flow through the hose 68 to the tube 56 where the air is directed to the distributing head 62 of the pressure plate 61. The air passes through the distributing head aperture 63 to the crucible I2 forcing the molten metal therein through the sprue hole II to the cavity l0. When the handle or operating lever 49 reache its final position the latch 14 drops by gravity about its pivot 19 in front of the abutment bolt I1 and retains the parts in this position. As soon as the casting operation is complete pressure is applied to the lever 49 to release the latch 14 whereupon its nose I is grasped for elevating the same and the pressure then released from the handle. The spring 29 and Bil immediately expand and return the parts to the positions illustrated in Fig. 1. The handle 49 is then manually raised to its uppermost position and the ring M with its embedded casting re moved and processed in accordance with the usual custom.

From the foregoing it will now be seen that there has been provided a casting machine which will accomplish the objects initially set forth.

What is claimed is:

1. In a casting machine the combination of a base member, a mold supporting plate having a central recess therein and an aperture centrally of the recess, a bolt carried by the base extending through the support aperture and having a head disposed in the recess, and a spring around said bolt abutting on opposite ends with the supporting plate and base for causing the support to be elevated above the base and whereby pressure on the support will cause said support to be yieldably lowered toward the base.

2. In a casting machine the combination of a base member, a mold supporting plate having a central recess therein and an aperture centrally of the recess, a bolt carried by the base extending through the support aperture and having a head disposed in the recess, and a spring around said bolt abutting on opposite ends with the" supporting plate and base for causing the support to be elevated above the base and whereby pressure on the support will cause said support to be yieldably lowered toward the base, said recess having the bottom thereof conically shaped and the bolt having the under surface of its head correspondingly conically shaped whereby a ball joint is provided between the supporting plate and bolt head to permt tilting of the support relative to the base.

3. In a casting machine the combination of a base member, a mold supporting plate having a central recess therein and an aperture centrally of the recess, a bolt carried by the base extend ing through the support aperture and having a head disposed in the recess, a spring around said bolt abutting on opposite ends with the supporting plate and base for causing the support to be elevated above the base and whereby pressure on the support will cause said support to be yieldably lowered toward the base, said base hav ing pivotally mounted thereon a handle, means on said handle for engagement with and a covering for a mold on the supporting plate for supplying compressed air to the mold and including a yieldable spring whereby the mold engaging and covering means may be deflected with respect to the mold and handle while the said parts are being brought into operative relation,

and means for connecting apressure source withthe mold engaging and covering means.

4. In a casting machine the combination of a base member, a mold supporting plate having a. central recess therein and an aperture centrally of the recess, a bolt carried by the base extending through the support aperture and having a head disposed in the recess, a spring around said bolt abutting on opposite ends with the supporting plate and base for causing the support to be elevated above the base and whereby pressure on the support will cause said support to be yieldably lowered toward the base, said base having pivotally mounted thereon a handle, means on said handle for engagement with and a covering for a mold on the supporting plate for supplying compressed air to the mold and including a yieldable spring whereby the mold engaging and covering means may be deflected with respect to the mold and handle while the said parts are being brought into operative relation. and mean for connecting a pressure source with the mold engaging and covering means, said connecting means including a valve operable upon movement of the mold supporting plate after the mold and covering means have been brought into engagement with the mold.

5. In a casting machine the combination of a base member, a mold supporting plate having a central recess therein and an aperture centrally of the recess, a bolt carried by the base'extending through the support aperture and having a head disposed in the recess, a spring around said bolt abutting on opposite ends with the supporting plate and base for causing the support to be elevated above the base and whereby pressure on the support will cause said support to be yieldably lowered toward the base, said base having pivotally mounted thereon a handle, means on said handle for engagement with and a covering for a mold on the supporting plate for supplying compressed air to the mold and including a yieldable spring whereby the mold engaging and covering means may be deflected with respect to the mold and handle while the said parts are being brought into operative relation, and means for connecting a pressure source with the mold engaging and covering means, said connecting means including a stationarily mounted valve,

and a lever intermediately mounted on the base having one end contacting the valve and the other the supporting plate whereby movement of the support actuates the lever for opening the valve.

6. In a casting machine of the class described a mold covering and pressure supplying mechanism comprising an air tube, a handle having an aperture therein through which the air tube freely passes, a spring around said air tube and abutting on opposite ends with the handle and an abutment 0n the air tube for moving the air tube in one direction, a collar on the air tube limiting the movement thereof by the spring, a pressure plate threadedly secured to the air tube below its spring abutment and said pressure plate having a threaded boss projecting therefrom, and a removable sealing member threaded on the pressure plate boss for engagement with the mold.

7. In a casting machine of the class described a mold covering and pressure supplying mechanism comprising an air tube, a handle having an aperture therein through which the air tube freely passes, a spring around said air tube and abutting on opposite ends with the handle and an abutment on the air tube for moving the air tube in one direction, a collar on the air tube limiting the movement thereof by the spring, a pressure plate threadedly secured to the air tube below its spring abutment and said pressure plate having a threaded boss projecting therefrom, a removable sealing member threaded on the pres sure plate boss for engagement with the mold, said sealing member being channeled on its under surface, and heat resisting sealing means packed in said channel for physical engagement with the mold.

8. In a casting machine of the class described a mold covering and pressure supplying mechanism comprising an air tube, a handle having an aperture therein through which the air tube freely passes, a spring around said air tube and abutting on opposite ends with the handle and an abutment on the air tube for moving the air tube in one direction, a collar on the air tube limiting the movement thereof by the spring, a pressure plate on the air tube below its spring abutment and said pressure plate having a threaded boss projecting therefrom, and a removable sealing member threaded on the pressure plate boss for engagement with the mold, said air tube collar having its under surface conically shaped, and said handle having a correspondingly shaped seat around its aperture through which the tube passes whereby the sealing plate and pressure plate may be'tilted universally with respect to the handle and whereby the air tube when urged to its normal free position by the spring will have its axis normal to the handle seat.

9. In a casting machine of the class described a mold sealing assembly having in combination with an air tube, a pressure plate threadedly secured to the end of the air tube, an externally threaded boss depending from the pressure plate, and a removable sealing plate threaded on the pressure plate boss.

10. In a casting machine of the class described a mold sealing assembly having in combination with an air tube, a pressure plate threadedly secured to the end of the air tube, an externally threaded boss depending from the pressure plate, and a removable sealing plate threaded on the pressure plate boss, said sealing plate having its under surface channeled and said channel being packed with heat and flame resisting material for physical contact with the mold.

AUGUST L. WEYHING. 

